Intraday you should stick to top 20 traded stocks. if you are a positional or swing trader, you can do well given you are playing it right.
yes, I have played with much more lots than that is in your question. That was the times of 2007-08, Won't take much to guess what happened in Jan' 2008.
I hope you understand about position sizing. If not please do that before playing with 10 or more lots.